Casting oxidizable metals



Patented July 31, 1923.

UNITE s ATES PATENT" orrics.

ADOLF BECK AND KARL GER-SBACH, or BITTERFELD, AND OSKAR HERMANN WEBER I OF GRIESHEIM-ON-THE-MAIN, GERMANY, ASSIGNORS TO THE FIRM:

CHEMISCHE FABRIK GRIESHEIM-ELEKTRON, OF ERAINKFORT-ON-THE-MAIN, GERMANY CASTING OXIDIZABLE METALS.

N 0 Drawing.

To all whom it may concern Be it known that we, AnoLr BECK and KARL (irnnsnacn, residing at Bitterfeld, and OSKAR HERMANN lVEnnn, residing at Griesheim-on-the-lllain, Germany, citizens of Germany, have invented certain new and useful Improvements in Casting OxidiZable Metals, of which the following is a specification.

Our invention refers to the art of casting metals and more especially to means for preventing easily oxidizable metals suh as magnesium and magnesium alloys from oxidizing in the mould.

The casting of easily oxidizable metals or metal alloys, as for instance of magnesium, involves the disadvantage that, more especially with sandy moulds which strongly delay the efiluence of heat from the molten metal, the m tal surface remains for too long a period at a temperature which favours oxidation. In consequence of the slight shrinkage of the superficially solidified metal, an air gap may be formed between the metal and the sand mould which facilitates the admission of air from the atmosphere, whereby an ignition'arising locally on the surface of the metal from any either themselves or in their oxidized state do not affect the metal. In addition thereto these materials act particularly. favourably by a special expenditure of heat being required for their evaporation or for the de velopment of the gases owing to a process of decomposition, as hereby an accelerated chilling of the metal on the surface takes place.

Application filed May 25, 1922. Serial No. 563,717.

khan/pie l[.-Pulv.erized sulfur is blown on to the dried sand mould oris deposited thereon in heated conditionin such a manner that the sulfur will adhere to the sand mould in the form of minute drops, or else it may be sprayed on to the latter in suit able solution. The sulfur, upon coming into contact with the cast metal, evaporates and d splaces and consumes the oxygen of the air by oxidizing to sulfur dioxide which escapes.

Castings produced in such a manner have a perfectly bright surface and are also free from porous spots underneath the skin.

The black wash according to the invention may be used in connection with all kinds ofmoulds. I

Te wish it to be understood that we do not desire to be limited to the particular substances and proportions described, for obvious modifications will occur to a person skilled in the art.

\Ve claim:

1. The method of casting magnesium and alloys containing same, consisting in dusting the mould, prior to casting the metal, with a material capable of giving off, in contact with the molten metal, a gaseous substance, which is more easily oxidizable than magnesium.

2. The method of casting magnesium and alloys containing same, consisting in causing sulfur vapors to be developed in the mould in contact with the cast magnesium.

In testimony whereof we aifixour signatures.

ADOLF BECK. KARL GERSBACH. OSKAR HERMANN WEBER; 

